Roof drain



Se. 22, 197 c. L. HAGEDORN ROOF DRAIN Filed Nov. 7, 1968 Attorney United States Patent 3,529,723 ROOF DRAIN Charles L. Hagedorn, Wade International Limited, 73 Railside Road, Don Mills, Ontario, Canada Filed Nov. 7, 1968, Ser. No. 774,083 Int. Cl. E03f 5/14 US. Cl. 210-163 3 Claims ABSTRACT OF THE DISCLOSURE A roof drain provided with a weir plate having a flow metering aperture, the weir plate being vertically adjustable to adjust the size of the aperture.

BACKGROUND OF THE INVENTION This invention relates to drain structures of the type disclosed in the co-pending application of John E. Emberson, United States application Ser. No. 516,470 filed Dec. 27, 1965 now Pat. No. 3,447,329, wherein a weir arrangement is provided for controlling the rate of flow of water from a flat or gently sloped roof area into the downpipe and hence into the storm sewer system.

In accordance with the teachings of the said co-pending application provision is made in the drain by providing one or more special flow passages which have been described as inverted parabolic notches which are sized and calibrated with respect to the average storm anticipated to provide the requisite drain flow control for the system. By virtue of their shape these notches or apertures are intended to provide a flow rate which is directly proportioned to the head of water to provide a controlled flow through the drain so that the capacity of the downpipe and sewer into which it feeds, will not be exceeded. As a result the roof on which such drains are adapted to be installed is transformed into a storage reservoir and the water is metered oil? the roof at a controlled rate. This arrangement enables the use of fewer drains than those with uncontrolled flow rate and smaller diameter downpiping with smaller sewers can be utilized giving important savings in installation costs.

In practice it has been found that it is desirable to install the roof drain from one quarter to one inch below the finished roof level with drains of the type disclosed in the said co-pending application 516,470. When the drain is set at the variable distance below the roof deck the bottom of the metering aperture or apertures is automatically placed at a random distance below the roof deck according to the particular drain installation so that the calculation of the formulae used in the rating of the roof drain which are based on the bottom of the aperture being located flush with the roof level are inaccurate. This inaccuracy could be quite substantial since the head of water on the weir could be up to an inch more than that used in the calculations where the drain is set at the maximum distance below the roof level.

.RELATED INVENTION The related invention is disclosed in the above-mentioned United States application Ser. No. 516,470 filed Dec. 27, 1965 now Pat. No. 3,447,329.

SUMMARY OF THE INVENTION Accordingly, it is the object of the present invention to overcome the above problems encountered with drains of the flow metering type by providing a drain arrangement where the flow controlling aperture or apertures can be adjusted to compensate for the distance that the roof drain is installed below the finished roof level, so that the drain will provide the actual flow control for which it was designed.

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In order to accomplish this object according to the invention, the drain is provided with what is usually referred to as a weir arrangement which is vertically adjustable so that irrespective of the position of the drain below the roof deck the bottom of the flow control or metering passage or aperture or apertures as the case may be will be level with the roof surface to provide the requisite flow control in proportion to the head of water standing on the roof.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood with reference to the accompanying drawings in which FIG. 1 is a part mid-vertical section, part diagrammatic view of a roof drain installation embodying the invention. FIG. 2 is a broken away perspective view of a drain of the type illustrated in FIG. 1 embodying the invention.

DETAILED DESCRIPTION OF THE INVENTION With reference to FIG. 1 there is illustrated a drain installation mounted in a roof comprising a deck 1 over which is applied fill 2 and an overlying covering or sheeting 3. The drain assembly generally designated at 10 which is mounted in an opening 4 in the roof deck has a body 6 clamped between an upper bearing pan 7 and an underdeck clam-p 8 by means of bolts 9. Secured on the body 6 is a flashing clamp 11 which supports a dome 12 that has apertures 13 therethrough that permits the water to enter the drain while screening out foreign objects.

The flashing clamp 11 carries a base 14 having a large central opening 17 which has upstanding corner walls 15 which are best seen in FIG. 2. These corner walls define openings 16 in each of four sides defined by the corner walls in the embodiment of the invention illustrated.

In the absence of any controlling device it will be appreciated that water oif the roof would flow into the .drain in essentially uncontrolled flow rates, depending upon the head of water on the roof, the flow being through the dome which restricts only foreign objects, through the openings .16 down through the central base opening 17 into the body 6 and out the outlet 18 pro- 'vided in the body to the drain system (not shown). Excessive flow rates through the openings 16 and 17 greater than the capacity of the drain system could, of course,

cause backing up problems at any point along the drain system.

According to the present invention means are provided to permit an accurately predetermined flow rate control through the openings 16, or in a particular case, through a single opening 16 if flow requirements so necessitate, irrespective of the location of the flashing clamp 11 relative to the upper surface of the roof covering 3.

To provide this flow control there is provided one or more Weir plates 19 adjustably mounted on the walls 15 extending upwardly from the base 14 so that they can be moved vertically to adjusted positions and then set against dislodgement. In this connection it will be seen that each of the weir plates 19' is provided with a pair of slots 20 through which operate clamping screws 21 to clamp the weirs in adjusted vertical positions on the walls 15. Each of the weir plates 19 is provided with a flow controlling passage or aperture 22 of the parabolic" type. These apertures are defined by side walls 23a and 2312 which lie on the curve of a parabola, the walls being widely separated at the bottom then rapidly approaching each other towards a knee 24 and then asymtotically approaching each other towards the top.

It has been found that the flow rate through such an opening or aperture 22 is directly proportional to the head of water standing against the 'weir plate 19. It will be understood however that in making calculations as to the flow rate through the aperture in designing a drainage system, the aperture bottom 25 is assumed to be at the bottom of the water head, that is, level with the roof covering 3 and the flow calculations through such a metering opening 22 are inaccurate the moment that the bottom of the opening 22 is displaced above or below the roof level.

According to the present invention therefore, the drainage system may be made to provide the flow rate in accordance with the design calculations for the system by providing for the adjustment of the weir plates 19 through the use of the slots 20 and clamping screws 21 to bring the bottoms of the metering openings 22 flush with the roof covering 3.

It will be appreciated that the actual volume of flow through the drain will depend upon the number of weir plates 19 which are employed. In FIG. 2 there are illustrated two such weir plates. However, the Corresponding openings on the other side of the base (not shown) may if desired be closed by plates corresponding to the weir plates 19 but omitting the metering open ings 22.

For sake of convenience provision is shown for the mounting of say 4 metering weir plates 19 but it will be understood that the actual physical shape of the weir mounting means, that is the support comprised by the base 14 and Walls 15, may vary at will, the only requirement being that there be provided a mounting on which a weir plate having a metering orifice is vertically adjustable so that its bottom may be set relative to the upper surface 3 of the roof deck.

In practice the vertical variations in the mounting of the drain relative to the upper roof surface 3 are something of the order of one inch and the vertical adjustment of the weir plates 19 is made to provide for full vertical adjustment to the extent of drain installation variations likely to be encountered.

I claim:

1. In a drain structure for removing water from a surface area an upstanding support having an opening therethrough leading to the interior of the drain, a weir plate mounted on said upstanding support and overlying said opening said weir plate having a flow metering aperture therein extending upwardly from a substantially horizontal base and forming a flow restricting means through said support opening, and means for providing vertical adjustment of the weir plate to vertically adjust the position of the base of said aperture relative to a surface area to be drained.

2. A device as claimed in claim 1 in which said weir plate is slotted and is secured to said upstanding support for vertical adjustment by clamping screws passing through said slots and into said wall.

3. A drain structure for removing water from a surface area with a controlled flow rate comprising a drain body having a drain outlet, an upstanding wall having an opening through which water from such surface area must pass to reach said drain body and outlet, and means controlling the flow of water through said wall opening, said means comprising a plate mounted on said upstanding wall across said openings, said plate having a flow regulating aperture formed therein, said aperture extending upwardly from a substantially horizontal base, and means mounting said plate for vertical adjustment whereby said substantially horizontal base of the flow controlling aperture is adapted to be vertically adjusted relative to a surface area to be drained.

References Cited UNITED STATES PATENTS 1,348,945 8/1920 Hirshstein.

1,791,512 2/1931 Sehurman.

2,246,390 6/1941 Smith 210-164 X 2,572,101 10/1951 Bloch 2l0463 X 2,572,208 10/1951 Sievert 2lO-166 2,740,490 4/1956 Matheis 210166 2,832,564 4/1958 Williams 251-326 3,349,917 10/1967 Strickland 210164 DENNIS L. TAYLOR, Primary Examiner US. Cl. X.R. 61-63 

